At present, there is an optical label serial transmission solution in an optical packet switching (OPS) system, that is, an edge device processes a to-be-switched optical packet signal, and sends an optical label and an optical packet payload to an optical switching device in a serial manner. Referring to FIG. 1, FIG. 1 is a schematic diagram of a time sequence of optical label serial transmission in the prior art. As shown in the figure, an optical label and a corresponding optical packet payload are separate by time, the optical label is sent first, and then the corresponding optical packet payload is sent. A time interval is reserved between a moment for sending the optical label and a moment for sending the optical packet payload. The time interval is referred to as a guard time, and the guard time needs to be greater than or equal to a period of time that the optical switching device requires to receive the optical label, generate a control signal, and set up an optical link for transmitting the optical packet payload.
However, generally, the guard time needs approximately one hundred nanoseconds. When the optical switching device needs to operate a complex algorithm to set up an optical link, a longer guard time is required. Within the guard time, no valid data is transmitted over a link between the edge device and the optical switching device. Therefore, a link resource is wasted and link resource usage is low.